From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3B7766BFC0 for ; Sat, 21 Jun 2025 19:12:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750533142; cv=none; b=fPEvNnrhfwXKHJwZWHGWGV+aEveNIc+x1WcCcY3mXb2GSplK2//jjwLXZjlUiukVuQhsbPBfCXUY+gKe+UpYutL3gL5yUlMpdxkI0m/sC/CKRuhUAKgdIXa8NXL4xfOAVUMzX7nocdlm1tg4Ny2Iqb+lSbf9C9ZzSePvH2mg990= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750533142; c=relaxed/simple; bh=MjI3arHxiaLd6kiYKl5oUIrg2f97H0q7JfnGOQ5rDb4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=lXbTiVH8FNnWw4hWwFLHGmO58R4OHe1qKqKieVx+G//tv26LfuvWcskK73y5rVvSx2Oy33UoPKdWmUcpTmCQtZHi8DHVCCguer5w9bpIxvMO0fpM0sBUmVKXXyyrSUL3OsPF99gtCW+ksOY7ZhuDfqb5kqJw1Cja6vcpHy4+CnM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J5iGXEEM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="J5iGXEEM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 643B9C4CEE7; Sat, 21 Jun 2025 19:12:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750533141; bh=MjI3arHxiaLd6kiYKl5oUIrg2f97H0q7JfnGOQ5rDb4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=J5iGXEEM1l4kWx+QN+2DPoJmHVuA2ElzfJ8rRTz8jTDO/Kdwpn4XaIfXStUjFwV6W jYSZBSqlZIshXvonwZKno/73n42jrG38mJojSlSAScGfs72MsVtt5xwz69P5TQpD5C A/ilzVLqTe3TmOWQJFfEkRpiLUdLv+uEvInL8Q1jUKDfY7qV9uMbauKH4R0B7kWDqu gxOCGOeYBgQhTD2eGjXpG+QsmOyPTGv1o34jCcnzCW85JBtycfvEKi07f6y17DdhT8 Jx2jWZpdZgnX4RHJ+BYl7/mjafHQfEMmCyhspW4NQku3bXoWxAQ2pFK8ejC+EhnGJ+ HUJsCdZ+Wp9TA== Message-ID: Date: Sat, 21 Jun 2025 14:12:19 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: AMDGPU - Regression: Black screen due to commit 16dc8bc27c2aa3c93905d3e885e27f1e3535f09a To: Walt Holman Cc: linux-kernel , mario.limonciello@amd.com, alexander.deucher@amd.com References: <48ff3e59-db6f-4870-8f0b-3c49dd4d865e@kernel.org> Content-Language: en-US From: Mario Limonciello In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 6/21/25 11:07 AM, Walt Holman wrote: > On Sat, Jun 21, 2025 at 11:03 AM Walt Holman wrote: >> >> On Sat, Jun 21, 2025 at 10:52 AM Mario Limonciello wrote: >>> >>> >>> >>> On 6/21/25 10:18 AM, Walt Holman wrote: >>>> Hello, >>>> >>>> With the latest drm fixes this week on 6.16-rc2, I am experiencing a >>>> black screen instead of the sddm greeter and the GPU appears to be >>>> locked up. I can ssh into the laptop and reboot it, but that's about >>>> it. I have bisected the commit to commit id: >>>> 16dc8bc27c2aa3c93905d3e885e27f1e3535f09a and upon reverting the >>>> commit, the system works as normal. The hardware is an Asus Rog >>>> Zephyrus G16 with AMD Ryzen AI 9 HX 370 w/ Radeon 890M video. I'm able >>>> to test patches etc.. if need be. >>> >>> Hi there, >>> >>> By chance do you have an OLED panel? If so can you please try the patch >>> attached to this bug? >>> >>> https://gitlab.freedesktop.org/drm/amd/-/issues/4338 >>> >>> Thanks, >>> >>>> >>>> 16dc8bc27c2aa3c93905d3e885e27f1e3535f09a is the first bad commit >>>> commit 16dc8bc27c2aa3c93905d3e885e27f1e3535f09a (HEAD) >>>> Author: Mario Limonciello >>>> Date: Thu May 29 09:46:32 2025 -0500 >>>> >>>> drm/amd/display: Export full brightness range to userspace >>>> >>>> [WHY] >>>> Userspace currently is offered a range from 0-0xFF but the PWM is >>>> programmed from 0-0xFFFF. This can be limiting to some software >>>> that wants to apply greater granularity. >>>> >>>> [HOW] >>>> Convert internally to firmware values only when mapping custom >>>> brightness curves because these are in 0-0xFF range. Advertise full >>>> PWM range to userspace. >>>> >>>> Cc: Mario Limonciello >>>> Cc: Alex Deucher >>>> Reviewed-by: Roman Li >>>> Signed-off-by: Mario Limonciello >>>> Signed-off-by: Alex Hung >>>> Tested-by: Daniel Wheeler >>>> Signed-off-by: Alex Deucher >>>> (cherry picked from commit 8dbd72cb790058ce52279af38a43c2b302fdd3e5) >>>> Cc: stable@vger.kernel.org >>>> >>>> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 41 >>>> +++++++++++++++++++++++++++-------------- >>>> 1 file changed, 27 insertions(+), 14 deletions(-) >>>> >>> >> >> Yes, I do have an OLED panel and that patch does make it visible >> again. It is still very dark, but visible. >> >> -Walt > > Upon rebooting again, the display was much brighter and is fine. Just > the first boot after that was dark. > > -Walt Thanks, this makes sense. I suspect that because 0 means "off" for your panel that the patch you bisected to exposed running at 0 (or near enough to 0) that it caused this behavior. That patch you tested will be upstreamed in a future promotion, and I think we can take it in a -fixes PR later in the 6.16 fixes cycle. But there is one more thing I would like to confirm - on your system can you run with drm.debug=0x106 on the kernel command line and share me the output from this debug print? https://github.com/torvalds/linux/blob/v6.16-rc2/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c#L4933